Polymerization process and catalyst



United States V Patent POLYMERIZATION PROCESS AND CATALYST Charles W. Moberly, Bartlesville, Okla., assignor to Phillips Petroleum Company, a corporation of Delaware No Drawing. Continuation-impart of application Ser. No. 372,685, June 4, 1964. This application Jan. 25, 1965, Ser. No. 427,965

8 Claims. (Cl. 260-935) This is a continuation in part of Ser. No. 372,685, filed June 4, 1964 and now abandoned.

This invention relates to the polymerization of olefins to form solid polymers. In one aspect it relates to an improved catalyst for such a polymerization. In another aspect it relates to a process for producing solid polymers of olefins in increased yields.

It is known in the art to polymerize aliphatic l-olefins such as propylene and l-butene to form crystalline solid polymers. Catalysts for such a process are often formed by mixing together a compound having a metal-carbon bond with a compound of a transition metal. The activities of various of these catalysts can be improved by the addition of other compounds. Thus, for example, a catalyst which forms on the admixing of an alkylaluminum halide with a titanium halide can be improved by the addition to this mixture of a third component such as an organic phosphine. Still other components can be added to increase activity. Catalysts and processes of this type are disclosed in United States Patents 2,832,759 (1958) and 3,051,692 (1962). It is also known to produce crystalline polypropylene in high yields by the use of a catalyst which forms on mixing a dialkylaluminum chloride or iodide with a complex which forms on the reaction of titanium tetrachloride with metallic aluminum. This type catalyst and process are disclosed in British Patent 940,178.

Catalysts of the organometal type vary widely in activity and in the properties of the polymers which they produce. In the production of crystalline polypropylene, it is desirable to obtain not only high yields in the polymerization process but also a polymer which has a flexural modulus of at least 200,000 p.s.i. Very few catalysts among the many of this type which have been proposed in the art produce polypropylenes having the required flexural modulus in yields sufliciently high to be economical. While there have been various proposals to modify the activity of catalysts of the type hereinbefore referred to, many of the adjuvants do not increase yield without damaging other properties of the polymer, such as flexural modulus.

An object of this invention is to provide an improved catalyst. A further object of the invention is to increase yields of polyolefins such as polypropylene without damaging other properties such as flexural modulus. A further object is to render catalyst systems having very low polymerization activity highly active. Other objects and advantages will become apparent to those skilled in the art upon considering this disclosure.

According to this invention, the yield and/or flexural modulus of polyolefins is improved by carrying out the polymerization with a catalyst system formed on mixing (a) a compound of the formula RA1X (b) a compound of the formula R M, (c) a titanium trichloride-aluminum 3,403,140 Patented Sept. 24, 1968 "ice trichloride complex prepared by reaction of titanium tetrachloride and aluminum and having the approximate formula TiC1 /3AlCl and (d) a compound having the formula R M'X wherein R in the foregoing formulae is selected from the group consisting of alkyl, aryl, cycloalkyl, alkenyl and cycloalkenyl radicals and combinations thereof such as alkaryl, aralkyl, etc., having 1 to 20 carbon atoms, more preferably 1 to 10 carbon atoms, M is a group V-A element, preferably phosphorus, M is a group I-A, II or IIIA metal, X is a halogen, preferably chlorine, bromine or iodine, y-i-z is equal to the valence of M, y is 1, 2 or 3, and z is 0 or 1. Compound (d) is preferably R Zn and most preferably dialkylzinc. (Periodic System of Lange, Handbook of Chemistry, 8th Edition, pages 56-57.)

In forming the foregoing catalyst, the molar ratio of organoaluminum halide (RAIX to organo-group V-A compound is in the range of 1:5 to 5:1, preferably 1:2 to 2:1. The molar ratio of RAlX to titanium complex (as TiCl /sAlCl is most frequently in the range 0.25 to 10:1, preferably 2:1 to 10:1, and more preferably 3:1 to 7:1. The molar ratio of R MX to titanium complex is in the range 0.25:1 to 5:1, preferably 0.25:1 to 3:1, and more preferably 0.5:1 to 1.5: 1. The stated ranges are those which provide the most satisfactory results. However, ratios outside these ranges can be used.

The compounds represented by the formula RAIX are well known in the art. Examples are ethylaluminum dichloride, ethylaluminum dibromide, ethylaluminum diiodide, n-propylaluminurn dichloride, n-amylaluminum dibromide, tert-butylaluminum dichloride, eicosylaluminum diiodide, cyclohexylaluminum dichloride, phenylaluminum dichloride, 3-methylphenylaluminum dibromide, paratolylaluminum difluoride, 4-pheny1-2-cyclohexenylaluminum difluoride, 3-propylbenzylaluminum dichloride, benzylaluminum diiodide, and alpha-naphthylaluminum dichloride. Preferably, an alkylaluminum dichloride is used.

The organo-group V-Acornpounds (R M) utilized to form the catalyst according to this invention are also well known in the art. They include triethyl phosphine, tri-nbutyl phosphine, ethyl di-tert-butyl phosphine, tricyclohexyl phosphine, triphenyl phosphine, the tritolyl phosphines, the tricresyl phosphines, tribenzyl phosphine, triethylamine, tribenzylamine, triphenylamine, tricyclohexylamine, trinonylamine, trihexadecylamine, trieicosylamine, trivinylamine, triallylamine, tri(5-octenyl)amine, tri(3-methylcyclopentyl)amine, tri( 3 allylphenyl)amine, tri(2-naphthyl)amine, tri(9-anthryl)amine, tripropylarsine, tri( phenylbutyl arsine, triethylarsine, triphenylarsine, tribenzylarsine, tri(IO-phenanthryDamine, tri(3-allylcyclohexyl)amine, tri(5,6-dimethyl-1-chrysenyl)amine, triethylstibine, tributylstibine, tri'benzylstibine, triphenylstibine, tridodecylstibine, trioctadecylstibine, tri(S-decenyl) stibine, tri(2 -pyrenyl)stibine, tri(2 -cyclohexenyl)stibine, triethylbismuthine, triphenylbismuthine, tribenzylbismuthine, trihexylbismuthine, tri(3-hexadeceny1)bismuthine, tri(3,4 dimethyl 5,6-diisobutyl-l-naphthyl)bismuthine, triallylbismuthine, tricyclopentylbismuthine, tri- (2,3-dihexylcyclohexyl)bismuthine, and the like.

The titanium chloride-aluminum chloride complex utilized according to this invention is also well known in the art. It can be formed by reacting titanium tetrachloride 3 with metallic aluminum. The complex can be represented by the formula 3TiCl -AlCl (or Ticl /sAlCl The organoinetal compounds (R MX used in accordance with this invention are also well known in the 0.005 to 10 weight percent, but concentrations outside this range are operative.

The product polymers in accordance with this invention can be recovered from the reaction mixture by procart. They include diethylzinc, diisopropylzinc, di-n-butyl- 5 esses well known in the prior art. Thus the product polyzinc, di-n-octylzinc, dicyclopentylzinc, dicyclohexylzinc, mer can be contacted with a chelating compound such as diphenylzinc, phenylparatolylzinc, di-betanaphthylzinc, a diketone to remove catalyst residues and further conn-butyllithium, diethylcadmium, diethylinagnesium, tritacted with a hydrocarbon such as n-pentane or liquid proethylaluminurn, triethylgallium, isooctylsodium, phenylpylene to remove remaining traces of catalyst and chelatpotassium, l-naphthylrubidium, ethylberyllium fluoride, ing agent as well as any small amount of polymer fraction 7-phenanthrylcalcium iodide, 3-hexylcyclohexylmercury which may be soluble in light hydrocarbons at temperabromide, allylbarinm chloride, dieicosylzinc, di-lO-hexatures of the order of 80 to 100 F. decenylindium chloride, trihexylboron, diethylaluniinum In the commercial production of polypropylene, it is chloride, triphenylgallium, tribenzylthallium, tri-Lnaphdesirable that the hydr-ocarobnsoluble content be mainthaccnylaluininum, 2 phenyl 4 cyclohexenylstrontium tained at a low level. One advantage of this invention is chloride, ditolylgallium bromide, tri(7,8-dimethylchrysthat product polymer contains only small amounts of hyenyl)aluminum, di(3,4 diisopropyl-7,S-diethylnaphthyl) drocarbon-sol uble fractions. gallium chloride, diallylmagnesium, dioctylgallium iodide, The following examples will further illustrate the inand the like. Mixtures of two or more of the compounds vention, although it is not intended that the invention be in each group of catalyst ingredients described can be limited thereto. employed if desired. Exampla I The olefins which are polymerizable in accordance with this invention are aliphatic olefins having up to 8 carbon In a series of runs illustrating specific embodiments of atoms per molecule. The greatest benefits are obtained in this invention, propylene was polymerized in a mass polymerization of aliphatic l-olefins having from 3 to 7 polymerization system, i.e. as liquid propylene without a carbon atoms per molecule, e.g. propylene, l-butene, 1- diluent. The catalyst was formed by mixing ethylaluminum pentene, l-heXene and 4-methyl-l-pentene. dichloride, triphenyl phosphine, titanium trichloride-alu- The polymerization is most frequently conducted in the minum chloride complex and diethylzinc, and about 0.1 temperature range to 250 F., and more frequently mol percent hydrogen was used in all runs. to 200 The pressure used is merely sutficient pressure 30 The polymer was recovered substantially as hereinto maintain the reaction mixture substantially in the liquid before described. In addition, other combinations of the phase. While an inert hydrocarbon diluent, e g. a paraffin, catalyst ingredients were utilized to illustrate the desircycloparafiin, or aromatic hydrocarbon having up to 20 ability of the four catalyst ingredients in accordance with carbon atoms per molecule, can be utilized, it is frequently this invention. The following results were obtained.

Run Tempera- M01 Ratio EADC: Total Catalyst Rate, gIlL/glll. Flex M0d., No. ture,F. P:EtQZn:TiCl3-% Coneen.,Wt. Ti 13 p.s.i.X10=' A1013 Percent Complex/hr.

1 Liquid.

advantageous to conduct the reaction without a diluent, especially when propylene is being polymerized. Under these circumstances, liquid propylene acts as the reaction medium. The reaction time is generally in the range 10 minutes to 20 hours, more frequently 30 minutes to 5 hours.

It is frequently desirable, for controlling the molecular weight of the polymer, to utilize from about 0.08 to about 0.30 rnol percent of hydrogen in the system. When propylene is being polymerized in a mass polymerization system, it is desirable to dissolve this amount of hydrogen in the liquid propylene before passing the propylene into the polymerization reactor.

The total catalyst concentration in the reaction mix- Example II A series of runs were carried out in the same manner as those of Example I. A 2.5 hour reaction period at 130 F. and 325 p.s.i.g. with 250 g. propylene and 1 liter H present was employed. The following results were obtures according to this invention is usually in the range 75 tained.

Mole Ratio EADC:

'lotal Catalyst Rate, g./g. of

Flex. Mod.

Run N 1: RyMXzZTiClg' R M RyM XZ Concn., Wt. T101 94 A1013] p.s.i. X

% A101 Percent hr.

5:5:221 l. 005 103 207 515:1:1 0. 923 103 237 5:5:2:1 1.008 286 79 5:5:lzl 0. 920 149 153 525:1:1 0.914 170 225 5:510. 5: 1 0. 872 124 225 5:5:0.25:1 0.875 55 231 525:2:1 0 967 94 251 5:5:1:1 .915 98 253 5:5:2:1 0. 981 175 252 5:5:1:1 0. 911 160 231 5:520. 5:1 0, 894 134 252 5:5:2:1 0.899 111 244 5:5:0:1 0.592 91 230 :2. 5:1. 5:1 0. 538 199 217 .5:2.5:2:1 0.580 174 200 :2.5:2.5:1 0.595 118 211 525:2:2 0. 512 382 100 :2.5:0:1 0.618 10 :2.5:l:1 0.679 40 244 2. 5:2. 5:11 0. 547 173 268 5:1. 5:1 0. 562 209 239 5:2. 0:1 0. 574 234 218 5:2. 5:1 0. 609 256 219 5252222 0. 527 206 160 :2. 5:1:1 0. 459 96 215 :2. 511:1 E 0. 329 171 195 :2. 5:021 (C3H5)3N 0.348 33 219 5: 1:1 (C3H5)3N- EtgAl. 0.664 163 221 :2. 5: 1 l (C H N EliaAl- 0. 526 64 229 :2. 5: 1: 1 (GaH5)3N EtgAl. 0. 389 158 206 1 ASTM D-790-61. 2 Based on propylene.

N ote. means phenyl; 132 means benzyl; Et means ethyl; n-Bu means n-butyl; and 0 11 is the allyl group.

Other catalyst systems according to my invention inelude:

Isopropyl aluminum dibromide Tris (2,4-dimethylphenyl phosphine Diisobutyl zinc Titanium trichloride-aluminum chloride complex Ethyl aluminum diiodide Tribenzyl phosphine Diethyl zinc Titanium trichloride-aluminum chloride complex n-Propylaluminum dichloride Triphenylamine Dicyclopentylcadmium Titanium trichloride-aluminum chloride complex Eicosylaluminum diiodide Tri Z-naphthyl) amine Triethylgallium Titanium trichloride-aluminum chloride complex Phenylaluminum dichloride Triphenylarsine Trieicosylboron Titanium trichloride-aluminum chloride complex p-Tolylaluminum dichloride Trioctadecylstibine T ribenzylthalliurn Titanium trichloride-aluminum chloride complex Benzylaluminum diiodide Triethylbismuthine Diallylmagnesium Titanium trichloride-aluminum chloride complex Cyclohexylaluminum dibromide Tri(2 -cyclohexenyl stibine Allylbarium chloride Titanium trichloride-aluminum chloride complex Cyclopentylaluminum dibromide Tricyclopentylarsine Ethylberylliuni fluoride Titanium trichloride-aluminum chloride complex Reasonable variations and modifications of this invention can be made, or followed, in view of the foregoing disclosure, without departing from the spirit or scope thereof.

I claim:

1. A process which comprises polymerizing an aliphatic l-olifin having up to 8 carbon atoms per molecule in the presence of a catalyst which forms on mixing a compound having the formula RAlX a compound having the formula R M, a titanium trichloride-aluminum trichloride complex having the formula TiCl /sAlCl and a compound havin the formula R MX wherein R in the formulae is selected from the group consisting of alkyl, cycloalkyl, aryl, alkenyl and cycloalkenyl radials having from 1 to 20 carbon atoms per molecule and and combinations thereof, X is a halogen, M is a group V-A element, M is a member of the group consisting of zinc, cadmium, aluminum, gallium and lithium metals, y-l-z is equal to the valence of M, y is an integer from 1 to 3, and z is an integer from 0 to 1, wherein the molar ratio of the compound having the formula RAlX to the compound having the formula R3M is in the range of 1:5 to 5 :1; the molar ratio of the compound having the formula RAlX to titanium trichloride-alu-minum trichloride complex is in the range of 0.25 to 10:1; and the molar ratio of the compound havin the formula R M'X to titanium trichloride-aluminum trichloride complex is in the range of 0.25:1 to 5:1.

2. A process according to claim 1 wherein the catalyst is formed by mixing ethylaluminum dichloride, triphenyl phosphine, titanium trichloride-aluminum chloride complex and diethylzinc.

3. A process according to claim 1 wherein the catalyst is formed by mixing ethylaluminum dichloride, triphenyl phosphine, titanium trichloride-aluminum chloride complex and diethylcadmium.

4. A process according to claim 1 wherein the catalyst is formed by mixing ethylaluminum dichloride, triphenyl phosphine, titanium trichloride-aluminum chloride complex and triethylaluminum.

5. A process according to claim 1 wherein the catalyst is formed by mixing ethylaluminum dichloride, triallylamine, titanium (dichloride-aluminum chloride complex and triethylaluminum.

6. .A process according to claim 1 wherein the catalyst is formed by mixing ethylaluminum dichloride, tribenzylamine, titanium trichloride-aluminum chloride complex and triethylaluminum.

7. A process which comprises polymerizing, propylene in the presence of a catalyst Which forms on mixing an alkylaluminum dichloride wherein the alkyl group contains from 1 to 10 carbon atoms, a triaryl phosphine wherein the aryl groups contain up to 10 carbon atoms each, a titanium trichloride-zaluminum trichloride complex having the formula TiCl /3AlCl and a dialkylzinc wherein the alkyl groups have from 1 to 10 atoms each, the polymerization being conducted in the liquid phase at a temperature in the range 80 to 250 F., the molar ratio of alkylaluminum chloride to phosphine being in the range 1:5 to 5: 1, the molar ratio of alkylaluminum chloride to titanium chloride complex being in the range 0.25:1 to 10:1, and the molar ratio of dialkylzinc to titanium trichloride complex being in the range 0.25:1 to 5:1.

8. A proces which comprises polymerizing propylene at a temperature in the range 100 to 200 F. in the presence of a catalyst which forms on mixing ethlyaluminum dichloride, triphenyl phosphine, titanium trichloridealuminum trichloride complex having the formula TiCl /3AlCl and diethylzinc, the molar ratio of ethylaluminum dichloride to triphenyl phosphine being in the range 1:2 to 2:1, the molar ratio of ethylaluminum dichloride to titanium chloride complex being in the range 3:1 to 7:1, and the ratio of diethylzinc to titanium chloride complex being in the range 0.5 :1 to 1.5 :1.

References Cited UNITED STATES PATENTS 3,245,973 4/1966 Natta et a1. 26093.7 3,240,773 3/1966 Boor 26093.7 3,222,337 12/1965 Coover et a1. 26088.2 3,168,506 2/1965 Hoeg et al 26093.7 3,155,626 11/1964 Boor 26093.7 3,147,241 9/1964 Moberly 26093.7 3,081,287 3/1963 Coover et al. 26093.7 3,010,787 11/1961 Tornqvist 26093.7 2,971,925 2/1961 Winkler 252-429 FOREIGN PATENTS 880,747 10/1961 Great Britain.

OTHER REFERENCES Kresser, Polypropylene, Reinhold Publishing Corp, New York, 1960, TP 986, P56K72, pages 4950.

JOSEPH L. SCHOFER, Primary Examiner.

M. KURTZMAN, Assistant Examiner. 

1. A PROCESS WHICH COMPRISES POLYMERIZING AN ALIPHATIC 1-OLIFIN HAVING UP TO 8 CARBON ATOMS PER MOLECULE IN THE PRESENCE OF A CATALYST WHICH FORMS ON MIXING A COMPOUND HAVING THE FORMULA RA1X2, A COMPOUND HAVING THE FORMULA R3M, A TITANIUM TRICHLORIDE-ALUMINUM TRICHLORIDE COMPLEX HAVING THE FORMULA TICL3$1/3ALCL3 AND A COMPOUND HAVING THE FORMULA RYM''XZ, WHEREIN R IN THE FORMULAE IS SELECTED FROM THE GROUP CONSISTING OF ALKYL, CYCLOALKYL, ARYL, ALKENYL AND CYCLOALKENYL RADIALS HAVING FROM 1 TO 20 CARBON ATOMS PER MOLECULE AND AND COMBINATIONS THEREOF, X IS A HALOGEN, M IS A GROUP V-A ELEMENT, M'' IS A MEMBER OF THE GROUP CONSISTING OF ZINC, CADMIUM, ALUMINUM, GALLIUM AND LITHIUM METALS, Y+Z IS EQUAL TO THE VALENCE OF M'', Y IS AN INTEGER FROM 1 TO 3, AND Z IS AN INTEGER FROM 0 TO 1, WHEREIN THE MOLAR RATIO OF THE COMPOUND HAVING THE FORMULA RALX2 TO THE COMPOUND HAVING THE FORMULA R3M IS IN THE RANGE OF 1:5 TO 5:1; THE MOLAR RATIO OF THE COMPOUND HAVING THE FORMULA RALX2 TO TITANIUM TRICHLORIDE-ALUMINUM TRICHLORIDE COMPLEX IS IN THE RANGE OF 0.25 TO 10:1; AND THE MOLAR RATIO OF THE COMPOUND HAVING THE FORMULA RYM''X2 TO TITANIUM TRICHLORIDE-ALUMINUM TRICHLORIDE COMPLEX IS IN THE RANGE OF 0.25:1 TO 5:1. 